Draft Genome Sequence
David Neale and Charles Langley (UC Davis) worked with the California Walnut Board to sequence the walnut genome, currently released as v2.0. A manuscript is expected soon. Links:

Reference Genome V1.5
Stevens et al. produced draft genomes for Juglans regia, five additional Juglans species (J. nigra, J. sigillata, J. microcarpa, J. catheyensis, and J. hindsii) and the related species Pterocarya stenoptera. This J. regia assembly is not annotated and is available for download only.